Resistance

Version 0.12: This article may not be up to date for the latest stable release of Crawl.

For the ego found on robes and shields, see resistance (ego).

Monsters and players may have resistances against various types of damage; these are a subcategory of intrinsics.

Types of resistance

There are five "major" resistances. These are commonly granted by items, spells, or species-specific or random mutations:

• Fire resistance
• Cold resistance
• Negative energy resistance (aka life protection), which is resistance against draining attacks, necromantic magic, etc.
• Electricity resistance
• Poison resistance

The degrees to which characters may have resistance to these elements vary from resistance to resistance:

• Fire/cold resistance: can vary from rF/rC--- to rF/rC+++. Having any level of vulnerability increases damage done by 50% from missile attacks and 100% from melee attacks and clouds, but a character with rF--- will take no more damage from fire attacks than a character with rF-. All player sources of resistance/vulnerability stack.
• Negative energy resistance: can vary from none to rN+++. All sources stack, and rN+++ provides complete immunity. Vulnerability does not exist.
• Electricty resistance: Player can only have one level, rElec, which provides 66% damage reduction. Vulnerability does not exist, and sources do not stack.
• The player can have four levels: rPois-, none, rPois, or rPois+++. Vulnerability is only obtained by being in Spider Form, while immunity (rPois+++) is only obtained by being undead, including being in lichform. Sources of rPois do not generally stack. The one exception to this is that poison vulnerability and poison resistance will cancel each other out to leave a character with no resistance.

Damage reduction

Monsters and players with resistance will take less damage (or no damage) from a resisted attack. Some attacks are only partly resisted – for instance, only 45% of the damage from Fire Storm will have resistance (or vulnerability) applied to it.

Resistance is more effective vs. Sticky Flame, electrical attacks, and miasma.

The damage reduction for players is:

Resistance level	Damage taken	Dam. vs. sticky/elec./mias.
1	50%	33%
2	33%	25%
3	20%	17%

Note that players can only ever gain one level of electricity resistance. Monsters, however, can have more than one.

Monsters' resistance is more effective:

Resistance level	Damage taken	Dam. vs. sticky/elec./mias.
1	50%	33%
2	20%	17%
3	0%	0%

It is also possible for the player to be vulnerable (i.e., to have negative resistance) to fire, cold, or poison. Monsters can be vulnerable to fire, cold, poison, and electricity, and evil creatures (including the player, if undead, demonspawn, or in lichform) are vulnerable to cleansing flame. Vulnerability (of any degree) causes a creature to take 150% normal damage from missiles and 200% damage from all other attacks.

Life protection is handled differently: each level reduces damage taken by a third, meaning level 3 provides total immunity to draining and necromancy. Torment is also resisted by life protection, using yet another formula.

Gaining Resistances

• Quaffing a potion of resistance will give you one level of fire, cold, electricity and poison resistance for a while.
• Various dragon hides or armours, as well as other ego armour, will provide various major or minor resistances if worn.
• Most resistances (not electricity) can be gained by wearing particular (standard) items of jewellery.
• Artifacts may provide one or more resistances, including electricity resistance and some of the "minor resistances" below.
• All major resistances can be gained through a corresponding mutation (although only demonspawn can gain the life protection mutation).
• Some species have racial resistances or vulnerabilities. Notably, all the playable undead races have at least Cold Resistance 1, Life Protection 3, Poison Resistance, and Immunity To Torment.
• Many spells in the Transmutations school provide assorted resistances along with their other, more dramatic effects.

Minor Resistances

There are also a few "minor" resistances which come from specific items or species characteristics.

• Acid resistance protects you from acid, but not your items. It can come from an amulet of resist corrosion or randart, the Yellow Scales mutation (gained by yellow draconians), or the unrand Maxwell's patent armour. Acid damage is also reduced by wearing as many pieces of armour as possible (especially a cloak), which usually necessitates corrosion resistance, below.
• Corrosion resistance can be gained from an amulet of resist corrosion, a randart, or Maxwell's Patent Armour. Corrosion resistance gives your items a 90% chance to resist being corroded. Armour and weapons with high enchantments are more resistant to corrosion, as are sets of crystal plate armour and anything of dwarven make. Artefacts are completely immune to corrosion.
• Steam resistance from steam dragon armour. Fire resistance will also grant some resistance to steam.
  • Similarly, mottled dragon armour (and the artifact faerie dragon armour) grants resistance to sticky flame.
• Rot resistance comes from being undead, including being in lichform. It does not protect ghouls against their own random rotting, and all undead will still rot instead of mutating. Characters in Statue Form and demonspawn with the Foul Stench mutation also receive rot resistance. Rot resistance also confers resistance to sickness and immunity to miasma.
• Torment resistance will reduce damage from monsters casting Symbol of Torment or when using a scroll of torment.
• Mutation resistance comes from the amulet of that name (or artifacts), prior mutations, or high piety with Zin. From the amulet (its most common source), it is only 90% reliable. While undead will always rot instead of mutating, mutation resistance will block that rotting with the same frequency it would block mutation for a living character.
• A few other intrinsics act like specialized resistances: clarity (confusion, frenzy, amnesia), conservation (item destruction), sustain abilities (stat loss), stasis (slow, teleport, paralysis, etc.)
• Although some monsters are resistant to silence and hellfire, these are not available for players.

History

• Prior to 0.15, wearing a cloak of preservation was the usual choice to prevent item destruction. The concepts of item destruction and permanent corrosion effects retired at the same time.
• Elemental (Fire, Cold, and Electricity) resistances for players were nerfed in 0.6.
• Poison resistance for living characters was nerfed to provide only 90% protection against poisonous melee attacks in 0.10.